Field of the Invention
The present invention relates to a method of producing an optical fiber with a low transmission loss for use in an optical communication system. More particularly the present invention is directed to a method of producing a "preform rod" comprising a core glass and a cladding glass by applying a chemical vapor deposition process, which rod is then heated and drawn to form a fiber.
This particular method, in general, has the advantage that an optical fiber with low transmission loss, that is, without unreasonable attenuation of light, can be provided. This is because the process, from generation of vapors of the glass materials to formation of the core glass layer, is carried out in a closed system, with the result that doping of water and other impurities into the glass is avoided.